Electric servo dump gate system on a crop duster

ABSTRACT

The present invention is an Electric servo system which controls and automates gate openings based on GPS speed and position data that results in precise and reliable modern variable and constant rate application. The Electric servo system also allows for Mechanical gate linkages to remain intact, resulting in few changes to the aircraft and redundancy of emergency components. A Mechanical input connect/disconnect is used to effortlessly transfer between the automated Electric servo system and the Mechanical gate system.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application claims the priority to U.S. ProvisionalApplication No. 62/743,383, filed on Oct. 9, 2018, the disclosure ofwhich is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to a crop duster dump gatesystem, and more particularly to an electric servo dump gate system on acrop duster.

Description of Related Art

A crop duster dump gate opens and closes to turn on and off the flow ofpayload out of the hopper. The traditional Mechanical gate, standardequipment on all crop dusters, is actuated by the pilot throughmechanical linkages. The effort required by the pilot to open and closethe gate requires significant force that can lead to fatigue or injury.This is a reliable but feature deprived system. The pilot mustconstantly manually adjust for ground speed variation or accept theundesired variations of application rate and non-uniform application.This is caused by not being able to tie to the GPS and have the gateadjust for the speed and rate fluctuations.

Another system that can be installed is a Hydraulic dump gate whichautomates gate openings and increases precision by variable and constantrate application. On the Hydraulic system, the traditional Mechanicalgate linkages and bell cranks are removed and replaced by a complexhydraulic actuator and controller that send commands to the gate. Largeamounts of equipment and man hours are required to support the Hydraulicsystem, motor, pump, valves and more. This Hydraulic system is veryexpensive and can weigh more than 200 lbs. A failure on the system oftenresults in a time-consuming installation of replacement parts before theaircraft can continue work.

Therefore, it is necessary to have a cost-effective way to obtain thebenefits of technological advancements of variable rate and constantrate application, while retaining simplicity, reducing weight, reducingmaintenance, and providing redundancy of emergency systems.

BRIEF SUMMARY OF THE INVENTION

Advancements in mechatronics have allowed Electric servo systems acompetitive advantage over the Hydraulic system. It allows the user toautomate gate openings and conduct precise and reliable variable andconstant rate application. The Electric servo system is a fraction ofthe cost and weight, due to the reduced number of parts andminiaturization of modern electronics. Brushless motors have allowedlonger part life and better power density solutions. The Electric servosystem also allows for Mechanical gate linkages to remain intact,resulting in fewer changes to the aircraft and redundancy of emergencycomponents. If there is a controller or electric servo failure, theaircraft can continue to work because the system reverts to the originalmechanical linkages to open and close the gate. Replacement of acontroller or electric servo is also a very quick and simpleinstallation.

In an exemplary embodiment of the present invention, there is disclosedan electric servo dump gate system on a crop duster. The electric servodump gate system on a crop duster includes an electric gate controlsystem, which comprises an electric gate controller and an electricservo, wherein the gate controller upon the actuation by the pilot sendscommands to the electric servo which controls the position of the gate.

In one embodiment, the electric gate control system further comprises aGPS system linked to the gate controller such that the system automatesthe gate opening based on real-time GPS tracking data and speed.

In one embodiment, the electric servo dump gate system further comprisesa mechanical gate control system, which includes mechanical gatelinkages with a lever allowing the pilot to actuate the gate.

In one embodiment, the mechanical gate control system includes a pilot'sinput bell crank with lever, connected to a lower bell crank by thepilot's input linkage; the lower bell crank is connected to a lowerhorizontal linkage, the other end of the lower horizontal linkage isconnected to an over center bell crank; a mechanical pilot disconnect,connected to the over center bell crank with the other end connected toan over center linkage; the over center linkage is connected to the dumpgate to open or close the gate.

In one embodiment, when the pilot's input bell crank lever is in thestowed position, the mechanical pilot disconnect is not connected, themechanical system is not completely linked, the gate is not controlledby the mechanical control. While, when the pilot's input bell cranklever is moved out of the stored position towards the open position,re-linking the mechanical system, allowing direct mechanical control ofthe gate.

In one embodiment, wherein the mechanical pilot disconnect includes fourparts: an input lever, an output cam, an open lug, and a spring-loadedengagement pin; wherein the spring-loaded engagement pin is configuredto engage into the output cam so that when the pilot's input crank leveris moved toward an open position the engagement pin can engage to theoutput cam and lock the input lever to the output cam, resulting inre-link of the mechanical gate control system, and directly control thegate.

In one embodiment, wherein the electric servo is over-powered andback-driven, or there would be a clutch to disengage so the gate can beactuated manually.

In an exemplary embodiment of the present invention, there is discloseda method of converting a traditional mechanical dump gate system to anelectric servo dump gate system on a crop duster. The method comprisesthe following steps: installing an electric gate controller in acockpit; disconnecting mechanical dump gate system at any location inbetween a pilot input bell crank and the dump gate; installing amechanical pilot disconnect at the location where the mechanical dumpgate system is disconnected; installing a back-drivable electric servoat any location near the dump gate; connecting the electric servo andthe electric gate controller to the aircraft power buss throughappropriate breakers; connecting the electric servo and the electricgate controller via electronics; and connecting the electric servo andthe dump gate via mechanical linkages or electronic connections.

In one embodiment of the method, the location is preferably between thelower horizontal linkage and the over center bell crank.

In one embodiment, the method further comprises installing a GPS in thecockpit and adding data connection between the gate controller and theGPS to allow the GPS to feed information on ground speed variations orrate changes.

In one embodiment of the method, the mechanical pilot disconnectcomprises an input lever, a spring-loaded engagement pin, an output cam,and an open lug. The spring-loaded engagement pin is configured toengage into the output cam so that when the pilot's input crank lever ismoved toward an open position the engagement pin can engage to theoutput cam and lock the input lever to the disconnect output cam,resulting in re-link of the mechanical gate control system, and directmechanical control of the gate. In an exemplary embodiment of thepresent invention, there is disclosed a dump gate system on a cropduster comprising a powered gate system; and a mechanical gate system;the powered gate system comprises a back-drivable servo, a gatecontroller, and a GPS; and the mechanical gate system comprises a seriesof cranks and linkages.

In one embodiment, the mechanical gate system further comprises amechanical pilot disconnect that once is engaged allows bypass of themechanical gate system, thereby the pilot can use the powered gatesystem; while in case of a failure of the powered gate system, theexisting dump gate can be controlled by simply moving the pilot inputbell crank from a stowed position towards an open position, this engagesthe mechanical control, the servo will go to the mode that allows it tobe back-driven, thereby the pilot can continue to work until the servosystem is repaired.

In one embodiment, the dump gate system further comprising an open/closeswitch, which can actuate the gate or the gate can tie to the GPS toautomate gate openings based on stored application data, speed, andlocation data.

The more important features of the invention have thus been outlined inorder that the more detailed description that follows may be betterunderstood and in order that the present contribution to the art maybetter be appreciated. Additional features of the invention will bedescribed hereinafter and will form the subject matter of the claimsthat follow.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangements of the componentsset forth in the following description or illustrated in the drawings.The invention is capable of other embodiments and of being practiced andcarried out in various ways. Also it is to be understood that thephraseology and terminology employed herein are for the purpose ofdescription and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conception,upon which this disclosure is based, may readily be utilized as a basisfor the designing of other structures, methods and systems for carryingout the several purposes of the present invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions insofar as they do not depart from the spirit and scope ofthe present invention.

The foregoing has outlined, rather broadly, the preferred feature of thepresent invention so that those skilled in the art may better understandthe detailed description of the invention that follows. Additionalfeatures of the invention will be described hereinafter that form thesubject of the claims of the invention. Those skilled in the art shouldappreciate that they can readily use the disclosed conception andspecific embodiment as a basis for designing or modifying otherstructures for carrying out the same purposes of the present inventionand that such other structures do not depart from the spirit and scopeof the invention in its broadest form.

BRIEF DESCRIPTION OF THE DRAWINGS

Other aspects, features, and advantages of the present invention willbecome more fully apparent from the following detailed description, theappended claim, and the accompanying drawings in which similar elementsare given similar reference numerals.

FIG. 1 is a view of an electric servo dump gate system on a crop dusterin accordance with one embodiment of the present invention.

FIG. 2 is a view of a mechanical pilot disconnect in accordance with oneembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As stated above, a crop duster dump gate opens and closes to turn on andoff the flow of payload out of the hopper. The Electric servo system isactuated by the pilot through a gate controller, or the gate controllercan be bypassed, and the gate can be manually actuated. When the pilotis using the gate controller he can have the controller linked to a GPSsystem and have the gate automatically adjust for changes in groundspeed or application rate changes. If the electric servo fails and stopsfunctioning, the pilot can re-connect the Mechanical gate linkages withthe lever, which allows the pilot to actuate the gate and continue work.The electric servo is over-powered and back-driven, or there would be aclutch to disengage; so the gate can be actuated manually. The pilotwill lose the added features provided by the GPS, but the mechanicalgate control remains.

The claimed invention differs from what currently exists. The currentMechanical gate has great reliability but cannot provide automatic andmodern application techniques. An expensive Hydraulic gate can beadjusted by the GPS to fully service his customers using moderntechnology. However, the heavy and complex control system reduces theuseful load of the aircraft. To compensate for the Hydraulic system'sweight and spatial requirements, the aircraft will have a reducedproduct capacity and other useful systems, such as the rinse tank, needto be removed from the aircraft. The complexity of the Hydraulic systemintroduces numerous points of failure. In the event of a failure, theproblem needs to be fixed before work could continue.

The cost-effective Electric servo system can retain the reliableMechanical gate as a secondary system and can perform modern applicationservices by coupling to the GPS. The Electric servo system has manyadvantages such as weighing less, taking up less space, is less complex,and is reliable. Therefore, less changes and weight are added to theaircraft which maximizes product capacity and allows for all usefulaircraft systems to be retained.

This invention is an improvement on what currently exists. Thetraditional Mechanical gate is unable to be controlled by the GPS toallow precision variable application of products to the crop. TheHydraulic system can connect to the GPS and allow precision variableapplication of products to the crop, but requires the elimination of theMechanical system and the addition of hundreds of pounds of equipment onthe aircraft. The Hydraulic system is an additional system that isrequired to function for the plane to work. The Electric servo system islight and simple and allows the traditional Mechanical gate to remain onthe aircraft as a ready standby. This provides the best of both worlds,a GPS connect gate to allow precision variable application, whilemaintaining the redundancy of the traditional Mechanical gate allowingthe plane to always work. There are no other systems currently able todo this.

The equipment used in the Hydraulic gate requires significant space andweight in the aircraft. It is a complex network of moving parts withpumps, accumulators, pressure sensors, control valves, hydraulic motorsand the electric controller that all need to run the gate system.Aircraft systems such as the rinse tank needs to be taken off toaccommodate the hydraulic gate. The invention claimed here solves thisproblem.

The Electric servo gate system only requires the electric controller andan electric servo motor to move the gate. The gate is stills actuated bythe pilot though a control interface on the controller and can directlycommand the electric servo to move. This system can automate gateopening based on real-time GPS tracking data and speed. From the pilot'sperspective, an Electric Servo gate system can perform all theoperations and functions that a Hydraulic gate can, but it requiressignificantly less equipment to support. The electric servo system has asimpler and less time-consuming installation, maintenance, and repair.Also, with limited components, the placement can be in more accessiblelocations or locations with lesser harmful chemical environments. Thiscreates a system that is easier to access and significantly reduces thework required by the mechanic.

Referring to FIG. 1 , there is disclosed a crop duster airplane 1 inaccordance with the present invention. The crop duster airplane 1 is anaircraft that has been built or converted for agricultural use ofdispensing product. The crop duster airplane 1 includes a payload hopper2, a cockpit 3, a dump gate 4, an over-center linkage 5, an over-centerbell crank 6, an Electric Servo 7, a mechanical pilot disconnect 8, alower horizontal linkage 13, a lower bell crank 14, a linkage for pilotinput 15, a pilot input bell crank 16, a gate controller 17, and a GPS19.

The payload hopper 2 is a storage tank for holding the product. Thecockpit 3 is the location inside the aircraft where the pilot sits. Thedump gate 4 is the door at the bottom of the hopper used to control therelease of dry product. The over-center linkage 5 is a linkage betweenthe dump gate and over-center bell crank of the dump gate system. Theover-center bell crank 6 is a bell crank for connecting the over centerlinkage 6 and lower horizontal linkage 13 of the dump gate system. TheElectric Servo 7, with back-drive output, which is a servo that isgeared or clutched to allow the output to be moved when the servo isoff. The mechanical pilot disconnect 8 is a clutch, lock, shear, or pinthat allows the disengagement of the pilot's side of the mechanicalsystem from the gate side.

In one embodiment, the mechanical pilot disconnect 8 includes aDisconnect Input Lever 9, a Disconnect Output Cam 10, and a DisconnectOpen Lug 11, and a Disconnect Engagement Pin 12. The Disconnect InputLever 9 is a lever that freely rotates on the over center bell crank 6with the other end connected to the lower horizontal linkage 13. TheDisconnect Output Cam 10 is a cam that is bolted over center bell crank6 with a lobe that will connect with the open lug 11 and a hole for theengagement pin 12. The Disconnect Open Lug 11 is a pin or lug mounted onthe Disconnect input lever 9. The lug will interfere with the Disconnectoutput cam 10, so the cam can never be in a more closed position thanthe Disconnect input lever 9. The Disconnect Engagement Pin 12 is aspring-loaded pin mounted on the Disconnect input lever 9 that whenallowed will lock into the output cam 10 connecting the input lever 9and output cam 10.

The lower horizontal linkage 13 is a linkage between the over centerbell crank 6 and lower bell crank of the dump gate system 14. The lowerbell crank 14 is a bell crank for connecting the lower horizontal 13 andbooster output linkages of the dump gate system. The Linkage for pilotinput 15 is the linkage off the pilot input bell crank 16 to the lowerbell crank 14. The pilot input bell crank 16 is the control lever in thecockpit used by the pilot to control the dump gate. The AG GPS 19 is anelectric navigational and work tracking device, which can be used toproduce locational data while retrieving or calculating crop-dusterspecific data such as aircraft ground speed, swath width, or desiredapplication rate.

The mechanical control system includes the components of the system thatare solely used for mechanical gate actuation.

The electric control system includes the components of the system thatare solely used for electric gate actuation, which are Gate Controller17, Electric Servo 7, and a GPS 19. The electric control system mayfurther include an Open/Close Switch 18, which is a two-position toggleswitch connected to the Gate Controller 17 that the pilot uses to selectdesired gate position.

Relationship Between the Components:

Referring to FIG. 1 , there is disclosed a crop duster airplane 1 inaccordance with the present invention comprising a payload hopper 2,normally in the fuselage over the spar. At the bottom of the payloadhopper is the dump gate 4. In the cockpit 3 is the pilot's input bellcrank 16. The pilot's input bell crank 16 is connected to the lower bellcrank 14 by the pilots input linkage 15. The lower bell crank isconnected to the lower horizontal linkage 13. The other end of the lowerhorizontal linkage is connected to the over center bell crank 6. Thisconnection is normally made through the Mechanical pilot disconnect 8,this would allow the gate to open and close while the pilot's input bellcrank remains in the closed position.

Referring to FIG. 2 , there is disclosed a Mechanical pilot disconnect 8in accordance with the present invention, which is made of the followingfour parts. The Disconnect Input Lever 9 that is allowed to rotate onthe over center bell crank with the opposite end connected to the lowerhorizontal linkage 13. Mounted on the disconnect input lever 9 is thespring-loaded Disconnect Engagement Pin 12 that can engage into theDisconnect Output Cam 10. If the pin is allowed to engage to the cam 10it would lock the Disconnect Input Lever 9 to the Disconnect Output Cam10, re-engaging the Mechanical pilot disconnect 8. The Disconnect OpenLug 11 is a pin or bump on the Disconnect Input Lever 9 that wouldinterfere with Disconnect Output Cam 10. This interference prevents theDisconnect Output Cam 10 from ever being in a more closed position thanthe Disconnect Input Lever 9. Therefore, the gate can never be moreclosed than the pilot's input bell crank. However, if the pilot's inputbell crank 16 is moved out of the stored position towards the openposition the Disconnect Engagement Pin 12 aligns and locks the inputlever 9 to the output cam 10, connecting the mechanical pilot disconnect8, re-linking the mechanical system, allowing direct mechanical controlof the gate.

The Electric servo 7 connects to the gate controls on the gate side ofthe mechanical pilot disconnect 8. The over center bell crank 6 isnormally where the Electric servo connects to the gate controls. Theoutput of the over center bell crank 6 is connected to the over centerlinkage 5. The over center linkage 5 is then connected to the dump gate4. All the bell crank's center pivot points are held to the crop dustervia anchor points. The Gate Controller 17 is mounted in the cockpitwhere it is accessible for the pilot to make adjustments. The Open/CloseSwitch 18 is mounted in the cockpit, close to the pilot's hand, for theplot to actuate the gate. The AG GPS 19, in the cockpit, is controlledby the pilot and can give status of the application and can dictate gateopenings based on speed and position data.

The Mechanical Control 20 consist of all parts from the Mechanical PilotDisconnect 8 to the Pilot Input Bell Crank 16. These components are onlyused to mechanically control the dump gate. The Electric Control 21 iscomposed of the electric servo 7 and all the control electronics. Theelectric control will not control the dump gate when the mechanicalcontrol is connected.

How the Invention Works:

When the crop duster is in flight and has product in the hopper, thedump gate opens and closes, controlling the flow of the product onto thecrops during application. When the mechanical pilot input isdisconnected, the pilot can use the gate controller 17 to command theelectric servo, which controls the position of the dump gate. The gatecontroller 17 can be connected to a GPS 19 to allow precision constantrate or variable rate application of products to the crop. Based on theGPS's location, the GPS 19 will give corresponding gate controller 17application data to the gate controller 17. The gate controller 17 willthen command the electric servo 7 to move gate 4 position for the propergate settings, to achieve a specific application rate in that location.

To disconnect Pilot Input Bell Crank 16 from the dump gate 4; theDisconnect Engagement Pin 12 needs to be manually pulled and theDisconnect input lever 9 moved to the stored position, this also movesthe pilot input bell crank 16 to its stored position. This disconnectoperation can only be done on the ground as you must pull the DisconnectEngagement Pin 12, which is located outside the aircraft. To reconnectthe mechanical pilot disconnect the operation is as simple as moving thepilot input bell crank out of its stored position towards an open gateposition. As soon as the pilot input bell crank is as open as the gate,both the disconnect open lug and disconnect engagement pin engage withthe disconnect output cam. The Disconnect open lug is a safety feature.If for any reason the engagement pin is unable to engage with the outputcam, the open lug ensures that the pilot will always be able tomechanically open the dump gate. The engagement pin also ensures thepilot can close the dump gate using the mechanical linkages.

One key feature of the Electric Servo system is the ability to controlthe gate even during controller or electric servo failure. The systemcan simply revert back to the Mechanical system when the pilot'smechanical input is connected, then the input bell crank controls theposition of the dump gate. This is done by having 2 key components, themechanical pilot input disconnect and an electric servo, withback-drivable output. The mechanical pilot disconnect allows the pilot'sinput bell crank lever to remain stationary when the gate controller isin operation, but does not remove the mechanical connections of the gatethrough the traditional Mechanical system. This is needed so under anyforeseeable failure mode there is a way for the pilot to open the dumpgate and dump the load. The second component, the electric servo, isneeded so the pilot can overpower and move the linkages. In a hightorque gear motor servo, it takes such an excessive force to back-drivethe servo that the pilot might not be able to back-drive the servo andmove the gate. The solution is one of two; using a clutch on the servooutput to allow the servo gearbox to be disengaged, greatly reducing theforce needed to back-drive the servo output. Or preferably a highertorque motor can be used that is geared to reduce the force required toback-drive the motor to an acceptable level. When you have a system thatcan work both by an electric servo or mechanical linkages you maintainultimate reliability while utilizing GPS to preform modern advancedservice capabilities the customers are require.

How to Make the Invention:

Assemble the system on the aircraft as described in the earliersections. Install the Gate Controller in the cockpit.

Install the Back-Drivable Electric Servo 7 connected to the over-centerbell crank 6 and the aircraft payload hopper 2.

Disconnect the Lower horizontal linkage 13 from the over center bellcrank 6.

Install the Mechanical Pilot Disconnect 8 between the over center bellcrank 6 and the lower horizontal linkage 13.

Connect the Electric Servo 7 and Gate Controller 17 to the aircraftpower buss through appropriate breakers. Connect the data lines betweenthe Electric Servo 7 and Gate Controller 17. Data lines can also beconnected from the Gate Controller 17 to the GPS 19, if desired. Oncethe installation is complete, energize the circuit breakers and thesystem will power on and start working.

All pieces are necessary. You may add a data connection to the GPS toallow the GPS to feed info on ground speed variations or rate changes.

The Mechanical pilot disconnect 8 can be located anywhere in between thepilot input bell crank 16 and the dump gate 4. However, it is preferablefor the Mechanical pilot disconnect 8 to be closer to the dump gate 4 tolimit the inertia in the servo-controlled system. The Electric servo 7can be located anywhere in between the Mechanical pilot disconnect 8 andthe dump gate 4.

How to Use the Invention:

First, install all the components into your aircraft, connect all thecomponents, and power the unit. When the Mechanical Pilot Disconnect 8is engaged and the Mechanical system is bypassed, the pilot can use theelectric gate controller 17. The simple “open close switch” can actuatethe gate or the gate can tie to the GPS to automate gate openings baseson stored application data, speed, and location data.

By pressing the “Set Position” button on the face of the electric gatecontroller, the unit will require a position opening to be entered; thedesired position may be in percentage of gate opening or inches of gateopening. The gate will open to the set position when the “open/closeswitch” is moved to the open position. If the “open close switch” ismoved to the close position the gate will close.

By pressing the “Constant” button on the face of the controller the unitwill enter constant rate mode. The desired position and desired groundspeed are entered into the electric gate controller. The controller willconstantly calculate an open position based upon the desired gateposition, desired ground speed, and actual ground speed. The equationis:

${{Open}\mspace{14mu}{Position}} = {{Desired}\mspace{14mu}{Position}*\left( \frac{{Actual}\mspace{14mu}{Ground}\mspace{14mu}{Speed}}{{Desired}\mspace{14mu}{Ground}\mspace{14mu}{Speed}} \right)^{2}}$

The gate will open to the calculated ‘open position’ when the “openclose switch” is moved to the open position; the gate will constantlyadjust to the appropriate open position at any given time based on theactual ground speed. If the “open close switch” is moved to the closeposition the gate will close. This function describes constant ratemode.

By pressing the “Variable” button on the face of the controller the unitwill enter variable rate mode. This mode relies on the GPS to be loadedwith application data that details specific coverage rates in differentfield locations. The desired gate position is now constantly sent fromthe GPS, determined by the coverage rates, to the gate controller basedon the actual aircraft location. As before, the controller willconstantly calculate an open position based on the desired gateposition, desired ground speed, and actual ground speed. The gate willopen to the calculated ‘open position’ when the “open close switch” ismoved to the open position. The gate will constantly adjust to the newopen position. If the “open close switch” is moved to the close positionthe gate will close.

Additionally, in the case of a failure of the Electric Gate System, theexisting dump gate bell crank can be used to control the dump gate bysimply moving the pilot input bell crank from the stowed positiontowards the open position. This engages the Mechanical Control. Theelectric servo will go to the mode that allows it to be back-driven. Inthis way the pilot can continue to work until the Electric Servo Systemis repaired.

While there have been shown and described and pointed out thefundamental novel features of the invention as applied to the preferredembodiments, it will be understood that the foregoing is considered asillustrative only of the principles of the invention and not intended tobe exhaustive or to limit the invention to the precise forms disclosed.Obvious modifications or variations are possible in light of the aboveteachings. The embodiments discussed were chosen and described toprovide the best illustration of the principles of the invention and itspractical application to enable one of ordinary skill in the art toutilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated All suchmodifications and variations are within the scope of the invention asdetermined by the appended claims when interpreted in accordance withthe breadth to which they are entitled.

Any modification made to the friction wrench including fundamental novelfeatures of this invention are within the scope of the invention wheninterpreted in accordance with the breadth to which they are entitled.

What is claimed is:
 1. An electric servo dump gate system on a crop duster comprising: an electric gate control system comprising: an electric gate controller; an electric servo connected to the electric gate controller and a dump gate; the electric gate controller upon actuation sends commands to the electric servo, which controls a position of the dump gate; and a mechanical gate control system comprising: a pilot input bell crank lever; a mechanical pilot disconnect; and, the mechanical pilot disconnect disengages a pilot side of the mechanical gate control system from an electric servo side of the dump gate when the pilot input bell crank lever is in a stowed position such that the mechanical gate control system does not control the dump gate and the electric gate control system controls the dump gate, and wherein when the pilot input bell crank lever is moved from the stowed position to an open position the mechanical pilot disconnect engages the dump gate when the electric gate controller fails or the electric servo fails such that the mechanical gate control system then controls the dump gate to open and close the dump gate and the electric gate control system no longer controls the dump gate to open and close the dump gate.
 2. The electric servo dump gate system of claim 1, wherein the electric servo and the electric gate controller are connected to an aircraft power buss through a breaker; and, the electric servo and the electric gate controller are connected through electronic connection.
 3. The electric servo dump gate system of claim 1 further comprising an open/close switch as a two-position toggle switch connected to the electric gate controller that is used to select a gate position; wherein the electric gate controller upon actuation of the two-position toggle switch sends commands to the electric servo.
 4. The electric servo dump gate system of claim 1 further comprising a GPS system linked to the electric gate controller such that the electric gate control system automates the dump gate opening based on real-time GPS tracking data and speed.
 5. The electric servo dump gate system of claim 1, wherein the mechanical pilot disconnect allows the pilot input bell crank lever to remain in the stowed position when the electric gate control system is in operation and allows the pilot input bell crank lever to be moved to the open position and re-link the mechanical system thereby allowing direct mechanical control of the dump gate when the electric gate controller fails.
 6. The electric servo dump gate system of claim 1, wherein the mechanical gate control system further comprising: a pilot input linkage connected to the pilot input bell crank lever; and, a lower bell crank connected to the pilot input linkage.
 7. The electric servo dump gate system of claim 6, wherein the mechanical gate control system further comprising: a lower horizontal linkage connected to the lower bell crank at one end and to the mechanical pilot disconnect at an opposite end of the lower horizontal linkage; an over center bell crank connected to the mechanical pilot disconnect at one end and connected to an over center linkage at an opposite end of the over center bell crank; and, the over center linkage connected to the dump gate at an opposite end of the over center linkage.
 8. The electric servo dump gate system of claim 7, wherein in case of failure of the electric gate control system, the over center linkage or the over center bell crank is used to control the dump gate by moving the pilot input bell crank lever from the stowed position to the open position and thereby the mechanical gate control system operates the electric servo.
 9. The electric servo dump gate system of claim 8, wherein the servo is back-driven by the mechanical gate control system.
 10. The electric servo dump gate system of claim 1 further comprising a clutch on an output of the electric servo to allow a servo gearbox to be disengaged such that the mechanical gate control system controls the dump gate.
 11. The electric servo dump gate system of claim 1 further comprising a torque motor that is geared to reduce a force required to back-drive the electric servo.
 12. The electric servo dump gate system of claim 1, wherein the mechanical pilot disconnect comprises an input lever, a spring-loaded engagement pin, an output cam, and an open lug.
 13. The electric servo dump gate system of claim 12, wherein the input lever freely rotates on the over center bell crank at one end of the input lever and with an opposite end of the input lever connected to the lower horizontal linkage.
 14. The electric servo dump gate system of claim 13, wherein the output cam is bolted to the over center bell crank and the output cam has a lobe for connecting with the open lug.
 15. The electric servo dump gate system of claim 14, wherein the open lug is mounted on the one end of the input lever and the open lug is configured to interfere with the output cam such that the output cam can never be in a more closed position than the input lever.
 16. The electric servo dump gate system of claim 13, wherein the output cam has a hole in the output cam surface and the hole receives the spring-loaded engagement pin.
 17. The electric servo dump gate system of claim 16, wherein the spring-loaded engagement pin is mounted on the one end of the input lever such that when actuated the spring-loaded engagement pin will lock into the hole of the output cam and connect the input lever and the output cam together.
 18. The electric servo dump gate system of claim 17, wherein when the pilot input bell crank lever is in the stowed position the mechanical gate control system is disconnected from the dump gate and the electric system controls the dump gate.
 19. The electric servo dump gate system of claim 18, wherein when the pilot input bell crank lever is moved to the open position the spring-loaded engagement pin will engage the hole on the output cam and lock the input lever to the output cam and thereby re-link the mechanical gate control system such that the mechanical gate control system controls the dump gate and the electric gate control system no longer controls the dump gate.
 20. The electric servo dump gate system of claim 12, wherein the spring-loaded engagement pin is configured to engage into the output cam when the pilot input bell crank lever is moved to the open position such that the engagement pin will engage to the output cam and lock the input lever to the output cam resulting in re-link of the mechanical gate control system to the dump gate and thereby the mechanical gate control system controls the dump gate and the electric gate control system no longer controls the dump gate. 